From: Leonard Crestez <leonard.crestez@nxp.com>
To: Philipp Zabel <p.zabel@pengutronix.de>,
Lucas Stach <l.stach@pengutronix.de>,
Richard Zhu <hongxing.zhu@nxp.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
Jingoo Han <jingoohan1@gmail.com>,
Bjorn Helgaas <bhelgaas@google.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Shawn Guo <shawnguo@kernel.org>,
Fabio Estevam <fabio.estevam@nxp.com>,
"A.s. Dong" <aisheng.dong@nxp.com>,
dl-linux-imx <linux-imx@nxp.com>,
"kernel@pengutronix.de" <kernel@pengutronix.de>
Subject: [PATCH v2] PCI: imx: Add imx6sx suspend/resume support
Date: Wed, 7 Nov 2018 13:57:03 +0000 [thread overview]
Message-ID: <984fcef6d928632241a4a3bce41e2645a304d335.1541598751.git.leonard.crestez@nxp.com> (raw)
Enable PCI suspend/resume support on imx6sx socs. This is similar to
imx7d with a few differences:
* The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
pcie control bits on 6sx.
* The pcie_inbound_axi clk needs to be turned off in suspend. On resume
it is restored via resume -> deassert_core_reset -> enable_ref_clk.
Most of the resume logic is shared with the initial reset after probe.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
Changes since v1:
* Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
path is still an if statement.
* Did not split imx6_pcie_clk_disable or call it from other paths, this
would bring complications and is somewhat unrelated.
* See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
2 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 2cbef2d7c207..54625569d0bc 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
}
}
static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
{
- reset_control_assert(imx6_pcie->turnoff_reset);
- reset_control_deassert(imx6_pcie->turnoff_reset);
+ struct device *dev = imx6_pcie->pci->dev;
+
+ /* Some variants have a turnoff reset in DT */
+ if (imx6_pcie->turnoff_reset) {
+ reset_control_assert(imx6_pcie->turnoff_reset);
+ reset_control_deassert(imx6_pcie->turnoff_reset);
+ goto pm_turnoff_sleep;
+ }
+
+ /* Others poke directly at IOMUXC registers */
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
+ break;
+ default:
+ dev_err(dev, "PME_Turn_Off not implemented\n");
+ return;
+ }
/*
* Components with an upstream port must respond to
* PME_Turn_Off with PME_TO_Ack but we can't check.
*
* The standard recommends a 1-10ms timeout after which to
* proceed anyway as if acks were received.
*/
+pm_turnoff_sleep:
usleep_range(1000, 10000);
}
static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
{
clk_disable_unprepare(imx6_pcie->pcie);
clk_disable_unprepare(imx6_pcie->pcie_phy);
clk_disable_unprepare(imx6_pcie->pcie_bus);
- if (imx6_pcie->variant == IMX7D) {
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
+ clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
+ break;
+ case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
+ break;
+ default:
+ break;
}
}
+static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
+{
+ return (imx6_pcie->variant == IMX7D ||
+ imx6_pcie->variant == IMX6SX);
+}
+
static int imx6_pcie_suspend_noirq(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
- if (imx6_pcie->variant != IMX7D)
+ if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_pm_turnoff(imx6_pcie);
imx6_pcie_clk_disable(imx6_pcie);
imx6_pcie_ltssm_disable(dev);
@@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
{
int ret;
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
struct pcie_port *pp = &imx6_pcie->pci->pp;
- if (imx6_pcie->variant != IMX7D)
+ if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_assert_core_reset(imx6_pcie);
imx6_pcie_init_phy(imx6_pcie);
imx6_pcie_deassert_core_reset(imx6_pcie);
diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
index 6c1ad160ed87..c1b25f5e386d 100644
--- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
+++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
@@ -438,10 +438,11 @@
#define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
#define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
#define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
#define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
+#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
#define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
#define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
/* For imx6ul iomux gpr register field define */
#define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
--
2.17.1
next reply other threads:[~2018-11-07 13:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 13:57 Leonard Crestez [this message]
2018-11-14 22:47 ` [PATCH v2] PCI: imx: Add imx6sx suspend/resume support Andrey Smirnov
2018-11-22 11:38 ` Lorenzo Pieralisi
2018-11-22 11:50 ` Lucas Stach
2018-11-22 15:24 ` Lorenzo Pieralisi
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